TPWD outlines multi‑agency plan as New World screwworm outbreaks rise in Mexico

The Texas Parks and Wildlife Department told commissioners on Nov. 5 that the New World screwworm — a parasitic fly whose larvae bore into living tissue of warm‑blooded animals — remains a credible threat to livestock, wildlife and the state's agricultural economy if it spreads north from recent outbreaks in Mexico.

Alan Kane, division director for the wildlife division, told the commission that the fly is endemic in parts of the Caribbean and South America and that recent detections in Nuevo Lef3n, Mexico (one near Sabinas Hidalgo and one southeast of Monterrey) involved single animals quickly treated and classified as inactive. Kane said controlling established infestations takes time and that early detection is critical.

Kane summarized the sterile‑insect technique, the eradication method historically used in the United States: pupa are irradiated to produce sterile adult males, which are released to mate with wild females that typically mate only once, preventing viable offspring and collapsing local populations. He said the only fly production facility in the Western Hemisphere is in Panama and reviewed a multi‑pronged USDA strategy announced earlier in 2025: investments in research and sterilization, a planned sterile‑fly facility in Edinburg for distribution, nearly 8,000 surveillance traps deployed in Mexico and along the U.S. border, and renovation or support for production capacity in Panama and Mexico.

Kane said Texas will support response efforts led by the Texas Animal Health Commission (TAHC) and USDA, focusing TPWD resources on wildlife surveillance, sample collection and live‑animal movement inspections under approved protocols. He listed partner agencies that are part of the state response team: TAHC, Texas A&M AgriLife, Texas Department of State Health Services, Texas Department of Agriculture, USDA APHIS, U.S. Fish & Wildlife Service, National Park Service, Texas Veterinary Medical Diagnostic Lab and USDA laboratories. Kane also said Governor Abbott directed creation of a screwworm response team that includes industry stakeholders such as cattle and deer associations.

Commissioners asked about the time horizon for eradication if infestations reach the United States and whether the U.S. distribution and production capacity will be fast enough. Kane said eradication historically has taken decades when an infestation becomes established, but that ramped‑up production and early detection reduce that risk; he added that Federal plans call for bringing pupae from Panama to U.S. facilities for finishing and release if necessary. Commissioners also asked whether other animals, such as horses or dogs, are susceptible; Kane said livestock and other warm‑blooded animals can be affected and he would confirm species‑specific movement rules with USDA.

Why it matters: TPWD's presentation framed the department's role in a broader interstate and federal response: TPWD will concentrate on surveillance of free‑range wildlife and hunter‑harvested animals, sample collection and coordination for live‑animal inspections but will generally follow USDA and TAHC guidance for large‑scale eradication tactics.

What's next: Kane said weekly calls continue with TAHC, USDA and industry groups. TPWD staff described targeted outreach to landowners in counties near recent Mexican detections and said decisions about federal facility timelines and their sufficiency will depend on federal implementation and trap detections.

Attribution: Alan Kane, Division Director, Wildlife Division, Texas Parks and Wildlife Department, provided the briefing and technical description of sterile‑insect control methods.